Lunar Meteorite: LaPaz Icefield 02205 & pairs

Listed in The Meteoritical Bulletin, No. 88

from Antarctic Meteorite Newsletter, vol. 26, No. 2, 2003

LaPaz Icefield 02205 (LAP 02205)

Location: LaPaz Ice Field, Transantarctic Mountains, Antarctica
Dimensions (cm): 10.0 x 8.5 x 5.5
Found: 2002 December or 2003 January
Weight (g): 1226.300

Lunar-Basalt

Macroscopic Description: Kathleen McBride. 95% of the exterior surface has black fusion crust. Small areas of material have been plucked out. The fusion crust exhibits a slight ropy texture with polygonal fractures. The interior consists of interlocking tan and white coarse-grained minerals. There are numerous criss-crossing fractures filled with black glass.

Thin Section (,6) Description: Tim McCoy, Linda Welzenbach. The section consists of coarse-grained unbrecciated basalt with elongate pyroxene (up to 0.5 mm) and plagioclase laths (up to 1 mm) (~60:40 px:plag), rare phenocrysts of olivine (up to 1 mm) and interstitial oxides and late-stage mesostasis. Shock effects include undulatory extinction in pyroxene and shock melt veins and pockets. Microprobe analyses reveal pigeonite to augite of Fs_26-80Wo_14-36, plagioclase is An_85-90Or_0-1 and a single olivine phenocryst is Fa₅₀. The Fe/Mn ratio in the pyroxenes averages ~60. The meteorite is a lunar olivine-bearing basalt.

Oxygen Isotope Analysis: T.K. Mayeda and R.N. Clayton. Our analysis for LAP 02205 gives: d ¹⁸O = +5.6 and d ¹⁷O = +2.7. This is consistent with a lunar basalt.

Listed in The Meteoritical Bulletin, No. 88

from Antarctic Meteorite Newsletter, vol. 27, No. 1, 2004

LaPaz Icefield 02224, LaPaz Icefield 02226, & LaPaz Icefield 02436 (LAP 02224, LAP 02226, and LAP 02436)

Location: LaPaz Ice Field, Transantarctic Mountains, Antarctica
Dimensions (cm): 5.0 x 5.0 x 4.0, 6.0 x 6.0 x 3.5, & 5.5 x 4.25 x 2.25
Found: 2002 December or 2003 January
Weight (g): 252.5, 244.1, & 58.970 (1 piece each)

Lunar-Basalt

Macroscopic Description: Kathleen McBride. 50-90% of these lunar meteorite exteriors are covered with shiny, black, striated fusion crust. The interior has a granular texture with interconnected linear mineral grains, black, white and brown in color. There are criss-crossing fractures that are filled with black glass.

Thin Section (,4, ,6, and ,4) Description: Tim McCoy, Linda Welzenbach. These sections consist of a coarse-grained unbrecciated basalt with elongate pyroxene (up to 0.5 mm) and plagioclase laths (up to 1 mm) (~60:40 px:plag), rare phenocrysts of olivine (up to 1 mm) and interstitial oxides and late-stage mesostasis. Shock effects include undulatory extinction in pyroxene and shock melt veins and pockets. Microprobe analyses reveal pigeonite to augite of Fs_20-80Wo_10-36, plagioclase is An_85-90Or_0-1 and a single olivine phenocryst is Fa₃₅. The Fe/Mn ratio in the pyroxenes averages ~60. The meteorites are lunar olivine-bearing basalt. These are almost certainly paired with LAP 0220.

Listed in The Meteoritical Bulletin, No. 89

from Antarctic Meteorite Newsletter, vol. 27, No. 3, 2004

LaPaz Icefield 03632 (LAP 03632)

Location: LaPaz Ice Field, Transantarctic Mountains, Antarctica
Dimensions (cm): 5.5 x 3.5 x 3.0
Found: 2003 December or 2004 January
Weight (g): 92.566 (1 piece)

Lunar-Basalt

Macroscopic Description: Kathleen McBride. ~75% of the exterior has shiny black fusion crust. The interior is pinkish-tan with white linear minerals and glass veins. This sample is paired with the LAP samples from the ’02 season.

Thin Section (,2) Description: Tim McCoy, Linda Welzenbach. The section consists of a coarse-grained unbrecciated basalt with elongate pyroxene (up to 0.5 mm) and plagioclase laths (up to 1 mm) (~60:40 px:plag), rare phenocrysts of olivine (up to 1 mm) and interstitial oxides and late-stage mesostasis. Shock effects include undulatory extinction in pyroxene and shock melt veins and pockets. Microprobe analyses reveal pigeonite to augite of Fs_27-52Wo_12-33, plagioclase is An₈₇Or_0-1 and a single olivine phenocryst is Fa_32-99. The Fe/Mn ratio in the pyroxenes averages ~60. The meteorite is a lunar olivine-bearing basalt and is almost certainly paired with LAP 02205, LAP 02226, LAP 02224 and LAP 0243.

Listed in The Meteoritical Bulletin, No. 90

from Antarctic Meteorite Newsletter, vol. 29(2), September, 2006 – LAP 04841

LaPaz Icefield 04841 (LAP 04841)

Location: LaPaz Ice Field, Transantarctic Mountains, Antarctica
Dimensions (cm): 5.0 x 2.5 x 2.5
Found: 2004 December or 2005 January
Weight (g): 55.992 (1 piece)

Lunar-Basalt

Macroscopic Description: Kathleen McBride. Dull, black fusion crust covers over 50% of the exterior. Some surfaces have shiny areas. The interior is a pinkish tan and white matrix with black glass filled veins.

Thin Section (,2) Description: Valerie Reynolds, Tim McCoy and Linda Welzenbach. The meteorite is almost certainly paired with the LAP 02205 pairing group. LAP 02205 was described as follows: The section consists of coarse-grained unbrecciated basalt with elongate pyroxene (up to 0.5 mm) and plagioclase laths (up to 1 mm) (~60:40 px:plag), rare phenocrysts of olivine (up to 1 mm) and interstitial oxides and late-stage mesostasis. Shock effects include undulatory extinction in pyroxene and shock melt veins and pockets. Microprobe analyses reveal pigeonite to augite of Fs_26-80Wo_14-36, plagioclase is An_85-90Or_0-1 and a single olivine phenocryst is Fa₅₀. The Fe/Mn ratio in the pyroxenes averages ~60. The meteorite is a lunar olivine-bearing basalt.

Randy Says…

At 1.93 kg, LAP is the largest basaltic lunar meteorite and the largest lunar meteorite from Antarctica.

There are six stones, all with nearly complete fusion crusts. They were found along a linear trend a few kilometers long over 3 field seasons.

Compositionally and mineralogically, the basalt resembles the basalts of the Apollo 12 site but they are distinctly younger (Elardo et al., 2013). The LAP basalts are compositionally indistinguishable from NWA 4734/10597 and are likely launch pairs. The LAP basalts are also likely launch pairs with NWA 032/479 and NWA 8632 (Korotev and Irving, 2021; Merle et al., 2024). Together these meteorites are sometimes designated the NNL launch pairs, which may also include basalt NWA 12008 and breccia NWA 14178.

More Information

Meteoritical Bulletin Database

LAP 02205 | 02224 | 02226 | 02436 | 03632 | 04841

Map

ANSMET Location Map

References

Alosius R. M. L., Busemann H., Krietsch D., and Maden C. (2024) A high-precision isotope investigation of indigenous krypton and xenon signatures in lunar mare basalts. 86th Annual Meeting of the Meteoritical Society, abstract no. 6374.

Anand M., Taylor L. A., Neal C., Patchen A. and Kramer G. (2004) Petrology and geochemistry of LAP 02 205: A new low-Ti mare-basalt meteorite, Lunar and Planetary Science XXXV, abstract no. 1626, Lunar and Planetary Institute, Houston.

Anand M., Taylor L. A., Neal C., Patchen A. and Kramer G. (2004) Petrology and geochemistry of LAP 02 205: A new low-Ti mare-basalt meteorite. Lunar and Planetary Science XXXV, abstract no. 1626.

Anand M., Taylor L. A., Floss C., Neal C. R., Terada K., and Tanikawa S. (2006) Petrology and geochemistry of LaPaz Icefield 02205: A new unique low-Ti mare-basalt meteorite. Geochimica et Cosmochimica Acta 70, 246-264.

Anand M., Tartèse R., Barnes J. J., Starkey N. A., Franchi I. A., and Russell S. S. (2013) Abundance, distribution, and isotopic composition of water in the Moon as revealed by basaltic lunar meteorites. 44th Lunar and Planetary Science Conference, abstract no. 1957.

Basilevsky A. T., Neukum G., and Nyquist L. (2010) Lunar meteorites: What they tell us about the spatial and temporal distribution of mare basalts. 41st Lunar and Planetary Science Conference, abstract no. 1214.

Calzada-Diaz A., Joy K. H., Crawford I. A., and Nordheim T. A. (2015) Constraining the source regions of lunar meteorites using orbital geochemical data. Meteoritics & Planetary Science 50, 214-228.

Chokai J., Mikouchi T., Arai T., Monkawa A., Koizumi E., Miyamoto M. (2004) Mineralogical comparison between LAP02205 and lunar mare basalts. Antarctic Meteorites XXVIII, 4-5.

Collins S. J., Righter K., and Brandon A. D. (2005) Mineralogy, petrology and oxygen fugacity of the LaPaz icefield lunar basaltic meteorites and the origin of evolved lunar basalts. Lunar and Planetary Science XXXVI, abstract no. 1141, 36th Lunar and Planetary Science Conference.

Day J. M. D. and Paquet M. (2020) Highly siderophile element abundances in mare basalts reflect late accretion to the Moon’s interior. 51st Lunar and Planetary Science Conference, abstract no. 1071.

Day J. M. D. and Taylor L. A. (2007) On the structure of mare basalt lava flows from textural analysis of the LaPaz Icefield and Northwest Africa 032 lunar meteorites. Meteoritics & Planetary Science 42, 3-17.

Day J. M. D., Taylor L. A., Patchen A. D, Schnare D. W., and Pearson D. G. (2005) Comparative petrology and geochemistry of the LaPaz mare basalt meteorites. Lunar and Planetary Science XXXVI, abstract no. 1419.

Day J. M. D., Pearson D. G., Taylor L. A. (2005) ¹⁸⁷Re-¹⁸⁷Os isotope disturbance in La Paz mare basalt meteorites. Lunar and Planetary Science XXXVI, abstract no. 1424.

Day J. M. D., Nowell G. M., Norman M. D., Pearson D. G., Chertkoff D. G., and Taylor L. A. (2006) Evidence for age-progressive melting of increasingly incompatible-element-enriched mantle reservoirs on the Moon?. Lunar and Planetary Science XXXVII, abstract no. 2235.

Day J. M. D., Taylor L.A., Hill E., Liu Y. (2005) Textural analysis and crystallization histories of the LaPaz mare basalt meteorites. Meteoritics & Planetary Science 40, A37.

Day J. M. D., Taylor L. A., Floss C., Patchen A. D., Schnare D. W., Pearson D. G. (2006) Comparative petrology, geochemistry and petrogenesis of evolved, low-Ti lunar mare basalt meteorites from the La Paz Icefield, Antarctica. Geochimica et Cosmochimica Acta 70, 1581-1600.

Day J. M. D., Pearson D. G., and Taylor L. A. (2007) Highly siderophile element constraints on accretion and differentiation of the Earth-Moon system. Science 315, 217-219.

Elardo S. M., Shearer C. K. Jr., Fagan A. L., Neal C. R., Burger P. V., and Borg L. E. (2012) Diversity in low-Ti mare magmatism and mantle sources: A Perspective from lunar meteorites NWA 4734, NWA 032, and LAP 02205. 43rd Lunar and Planetary Science Conference, abstract no. 2648.

Elardo S. M., Shearer C. K., Fagan A. L., Borg L. E., Gaffney A. M., Burger P. V., Neal C. R., and McCubbin F. M. (2013) The origin of young mare basalts inferred from lunar meteorites NWA 4734, NWA 032, and LAP 02205. 44th Lunar and Planetary Science Conference, abstract no. 2762.

Elardo S. M., Shearer C. K. Jr., Fagan A. L., Borg L. E., Gaffney A. M., Burger P. V., Neal C. R., Fernandes V. A., and McCubbin F. M. (2013) The origin of young mare basalts inferred from lunar meteorites Northwest Africa 4734, 032, and LaPaz Icefield 02205. Meteoritics & Planetary Science 49, 261–291. doi: 10.1111/maps.12239

Elardo S. M., Shearer C. K., Vander Kaaden K. E., McCubbin F. M., and Bell A. S. (2015) Petrogenesis of primitive and evolved basalts in a cooling Moon: Experimental constraints from the youngest known lunar magmas. 46th Lunar and Planetary Science Conference, abstract no. 2155.

Fernandes V. A. and Burgess R. (2006) Ar-Ar studies of two lunar mare rocks: LAP02205 and EET96008. Lunar and Planetary Science XXXVII, abstract no. 1145.

Fernandes V. A., Burgess R., and Morris A. (2009) ⁴⁰Ar-³⁹Ar age determinations of lunar basalt meteorites Asuka 881757, Yamato 793169, Miller Range 05035, LaPaz Icefield 02205, Northwest Africa 479, and basaltic breccia Elephant Moraine 96008. Meteoritics & Planetary Science 44, 805-821.

Fernandes V. A. S. M., Fritz J. P., Wünnemann K., and Hornemann U. (2010) K-Ar ages and shock effects in lunar meteorites. EPSC Abstracts, Vol. 5, EPSC2010-237.

Fritz J. (2012) Impact ejection of lunar meteorites and the age of Giordano Bruno. Icarus 221, 1183-1186.

Guiza B. G. and Day J. M. D. (2013) Insights into volcanism on the moon from quantitative textural analysis of mare basalts. 44th Lunar and Planetary Science Conference, abstract no. 1825.

Hallis L. H. Joy K. H. Anand M., and Russell S. S. (2007) Compositional analysis of the very-low-Ti mare basalt component of NWA 773 and comparison with low-Ti basalts, LAP 03632 & 02436. Lunar and Planetary Science XXXVIII, abstract no. 1703.

Hill E., Taylor L. A., and Liu Y. (2007) LaPaz 04841: Comparative petrology and textural study of a new lunar mare basalt meteorite. Lunar and Planetary Science XXXVIII, abstract no. 1399.

Hill E., Taylor L. A., Floss C., Liu Y. (2009) Lunar meteorite LaPaz Icefield 04841: Petrology, texture, and impact-shock effects of a low-Ti mare basalt. Meteoritics & Planetary Science 44, 87-94.

Isaacson P. J., Liu Y., Patchen A., Pieters C. M., and Taylor L. A. (2009) Integrated analyses of lunar meteorites: Expanded data for lunar ground truth. 40th Lunar and Planetary Science Conference, abstract no. 2119.

Isaacson P. J., Liu Y., Patchen A. D., Pieters C. M., and Taylor L. A. (2010) Spectroscopy of lunar meteorites as constraints for ground truth: Expanded sample collection diversity. 41st Lunar and Planetary Science Conference, abstract no. 1927.

Jolliff B. L., Zeigler R. A., and Korotev R. L. (2004) Petrography of lunar meteorite LAP 02205, a new low-Ti basalt possibly launch paired with NWA 032. Lunar and Planetary Science XXXV, abstract no. 1438.

Joy K. H., Crawford I. A., Russell S. S., and Kearsley A. (2004) Mineral chemistry of LaPaz Ice Field 02205 – A new lunar basalt. Lunar and Planetary Science XXXV, abstract no. 1545.

Joy K. H., Crawford I. A., Russell S. S., and Kearsley A. (2005) LAP 02205, LAP 02224 and LAP 02226 – Lunar mare basaltic meteorites. Part 1: Petrography and mineral chemistry. Lunar and Planetary Science XXXVI, abstract no. 1697.

Joy K. H., Crawford I. A., Russell S. S., and Kearsley A. (2005) LAP 02205, LAP 02224 and LAP 02226 – Lunar mare basaltic meteorites. Part 2: Geochemistry and crystallisation. Lunar and Planetary Science XXXVI, abstract no. 1701.

Joy K. H., Crawford I. A., Downes H., Russell S. S., and Kearsley A. T. (2006) A petrological, mineralogical, and chemical analysis of lunar mare basalt meteorite LaPaz Icefield 02205, 02224, and 02226. Meteoritics & Planetary Science 41, 1003-1025.

Koizumi E., Chokai J., Mikouchi M., Makishima J., and Miyamoto M. (2005) Crystallization of lunar mare meteorite LAP 02205, 68th Annual Meeting of The Meteoritical Society, abstract no. 5152.

Koizumi E., Chokai J., Mikouchi M., and Miyamoto M. (2005) Crystallization experiment on lunar mare basalt LAP 02205. Antarctic Meteorites XXIX, 32-33.

Koizumi E., Mikouchi T., Chokai J., and Miyamoto M. (2006) Crystallization of lunar basaltic meteorites Northwest Africa 032 and 479: Preservation of the parent melt composition and relationship to LAP 02205. Lunar and Planetary Science XXXVII, abstract no. 1586.

Korotev R. L. (2005) Lunar geochemistry as told by lunar meteorites. Chemie der Erde 65, 297-346.

Korotev R. L. and Zeigler R. A. (2007) Keeping up with the lunar meteorites. Lunar and Planetary Science XXXVIII, abstract no. 1340.

Korotev R. L. and Zeigler R. A. (2014) Chapter 6. ANSMET Meteorites from the Moon, Thirty-five Seasons of U.S. Antarctic Meteorites (1976–2010): A Pictorial Guide to the Collection (editors K. Righter, R. P. Harvey, C. M. Corrigan, and T. J. McCoy), 101–130, Special Publications 68, American Geophysical Union, Washington, D. C., 296 pages, ISBN: 978-1-118-79832-4.

Korotev R. L., Zeigler R. A., and Jolliff B. L. (2004) Compositional constraints on the launch pairing of LAP 02205 and PCA 02007 with other lunar meteorites. Lunar and Planetary Science XXXV, abstract no. 1416.

Korotev R. L., Irving A. J., and Bunch T. E. (2008) Keeping up with the lunar meteorites – 2008. Lunar and Planetary Science XXXIX, abstract no. 1209.

Korotev R. L., Zeigler R. A., Irving A. J., and Bunch T. E. (2009) Keeping up with the Lunar Meteorites – 2009. 40th Lunar and Planetary Science Conference, abstract no. 1137.

Merle R. E., Whitehouse M. J., Nemchin A. A., Deligny C., Kenny G. C., Larsen K. K., and Connelly J. N. (2024) Deciphering the origin of the chemical characteristics of the 3000 Ma-old chemical group of lunar basalts. 86th Annual Meeting of the Meteoritical Society, abstract no. 6317.

Mikouchi T. T., Chokai J., Arai T., Koizumi E., Monkawa A., and Miyamoto M. (2004) LAP02205 lunar meteorite: Lunar mare basalt with similarities to the Apollo 12 ilmenite basalt. Lunar and Planetary Science XXXV, abstract no. 1548.

Morris A., Fernandes V., and Burgess R. (2008) Ar-Ar ages for lunar basalt meteorites: A 881757, Y 793169, MIL 05035, LAP 02205, NWA479 and EET 96008. Goldschmidt Conference Abstracts 2008, Geochimica et Cosmochimica Acta 72, 12S, A652.

Nishiizumi K., Hillegonds D. J., and Welten K. C. (2006) Exposure and terrestrial histories of lunar meteorites LAP 02205/02224/02226/02436, MET 01210, and PCA 02007, Lunar and Planetary Science XXXVII, abstract no. 2369.

Nyquist L. E., Shih C.-Y., Reese Y., and Bogard D. D. (2005) Age of lunar meteorite LAP02205 and implications for impact-sampling of planetary surfaces. Lunar and Planetary Science XXXVI, abstract no. 1374.

Nyquist L. E., Shih C-Y., and Reese Y. D. (2007) Sm-Nd and Rb-Sr ages for MIL 05035: Implications for surface and mantle sources. Lunar and Planetary Science XXXVIII, abstract no. 1702.

Paniello R. C., Day J. M. D, and Moynier, F. (2012) Zinc isotopic evidence for the origin of the Moon. Nature 490, 376–379.

Rankenburg K., Brandon A., Norman M., and Righter K. (2005) LAP 02 205: An evolved member of the Apollo 12 olivine basalt suite?. 68th Annual Meeting of the Meteoritical Society, abstract no. 5294.

Rankenburg K., Brandon A. D., and Neal C. R. (2006) Formation interval of the lunar mantle from high-precision Nd-isotope measurements of six lunar basalts. 69th Annual Meeting of the Meteoritical Society, abstract no. 5036.

Rankenburg K., Brandon A. D., and Neal C. R. (2006) Neodymium isotope evidence for a chondritic composition of the Moon. Science 312, 1369-1372.

Rankenburg K., Brandon A. D. and Norman M. D. (2007) A Rb­Sr and Sm­Nd isotope geochronology and trace element study of lunar meteorite LaPaz Icefield 02205. Geochimica et Cosmochimica Acta 71, 2120-2135.

Righter K., Brandon A.D., and Norman M.D. (2004) Mineralogy and petrology of unbrecciated lunar basaltic meteorite LAP 02205. Lunar and Planetary Science XXXV, abstract no. 1667.

Righter K., Collins S.J., and Brandon A.D. (2005) Mineralogy and petrology of the LaPaz Icefield lunar mare basaltic meteorites. Meteoritics & Planetary Science 40, 1703-1722.

Schnare D. W., Taylor L. A., Day J. M. D., and Patchen A. D. (2005) Petrography and mineral characterization of lunar mare basalt meteorite LAP 02-224. Lunar and Planetary Science XXXVI, abstract no. 1428.

Spicuzza M. J., Day J. M. D., Taylor L. A., and Valley J. W. (2007) Oxygen isotope similarities and differences between the earth and moon: Can oxygen isotopes distinguish meteorites on the moon. Lunar and Planetary Science XXXVIII, abstract no. 2025.

Spicuzza M. J., Day J. M. D., Taylor L. A., and Valley J. W. (2007) Oxygen isotope constraints on the origin and differentiation of the Moon. Earth and Planetary Science Letters, 253, 254-265.

Taylor L. A and Day J. M. D. (2005) FeNi metal grains in La Paz mare basalt meteorites and Apollo 12 basalts. Lunar and Planetary Science XXXVI, abstract no. 1417.

Wang Y. and Hsu W. (2010) SIMS Pb/Pb dating of Zr-rich minerals from NWA 4734 and LAP 02205/02224: Evidence for the same crater on the Moon. 73rd Annual Meeting of the Meteoritical Society, abstract no. 5024.

Wang Y., Hsu W., Guan Y., Li X., Li Q., Liu Y., and Tang G. (2012) Petrogenesis of the Northwest Africa 4734 basaltic lunar meteorite. Geochimica et Cosmochimica Acta 92, 329-344.

Webb S., Neal C. R., Gawronska A., and Day J. M. D. (2019) Crystal size distribution patterns for lunar meteorites Northwest Africa 12008, 4898, 8632, 3136 and three LaPaz Icefield lunar meteorites. 50th Lunar and Planetary Science Conference, abstract no. 2686.

Will P., Maden C., and Busemann H. (2016) Noble gases in recently found hot and cold desert lunar meteorites. 79th Annual Meeting of the Meteoritical Society, abstract no. 6548.

Will P., Busemann H., and Maden C. (2018) Noble gases in glass and mineral grains separated from the unbrecciated lunar mare basalts Lapaz Icefield 02205, 02224, 02226, 02436. 81st Annual Meeting of the Meteoritical Society, abstract no. 6360.

Will P., Busemann H., Riebe M. E. I., and Maden C. (2022) Indigenous noble gases in the Moon’s interior. Science Advances 8. DOI: 10.1126/sciadv.abl4920

Yokoi N., Takenouchi A., and Mikouchi T. (2018) Iron valence states of plagioclase in some lunar meteorites. 49th Lunar and Planetary Science Conference, abstract no. 2227.

Zeigler R. A., Korotev R. L., Jolliff B. L., and Haskin L. A. (2005) Petrology and geochemistry of the LaPaz icefield basaltic lunar meteorite and source-crater pairing with Northwest Africa 032. Meteoritics & Planetary Science 40, 1073-1102.

Zhang A., Hsu W., Li X., Li Q., Liu Y., Tang G., and Jiang Y. (2010) Cameca IMS-1280 Pb/Pb dating of baddeleyite in LAP 02224. 41st Lunar and Planetary Science Conference, abstract no. 1080.

Zhang A., Hsu W., Li Q., Liu Y., Jiang Y., & Tang G. (2010) SIMS Pb/Pb dating of Zr-rich minerals in lunar meteorites Miller Range 05035 and LaPaz Icefield 02224: Implications for the petrogenesis of mare basalt. Science China Earth Sciences 53, 327-334. doi: 10.1007/s11430-010-0041-z.